do you consider Kerry King's guitar playing as shred?
if yes, then yep... i can shred.
at first, i didn't know it was shredding... when one says shred, i think of Yngwie Malmsteem... and man, i cant do decent arpeggio sweep picking (the basis for all yngwie type shred). but considering na parang bumaba yung "shred level" standard, i guess pumasok ako, hehehe.
i started with my right hand... tremolo picking = the reason why shred exists. if you just do pull's offs and hammer ons that will be more of a bluesy type playing (ala kirk hammett sa black album) ... tremolo picking + hammers and pulls = deceptively fast.
get those vibratos and whammy bar yanks up to par na rin... because thats how you emphasize notes (you start and end with them, as the cliche goes).
however, i have to tell you though, shredding really isnt all that... i have the worst note choices really, but because of the speed, ang dali dayain ng mga gitar lines mo... high gain + speed = mukha kang magaling. play all the scales you know just by tremolo picking and hammer ons and pull offs and im sure, papasok talaga yan sa E5 riff, hehehe...
merong mga magaling na shredders, na maganda talaga ang note choices at emphasis, at yung mga ganung type, kaya din nila mag play ng mga slow blues stuff... yung mga speed is king (like me) magaling lang right hand speed nun, pero kung sa note choices, usually bulok yan (like me... and of course, marami akong kilala na ganun, except akala nila magaling talaga sila).
anyway i suggest:
1.) you practice shred para sa right and left hand exercises (this is the easiest part) - tremolo picking, pull and hammers, whammy bar yanks, pinch harmonics, tapping (although may sariling mundo din to apart from shred) and palm mute with string skipping.
2.) practice blues for the note choices. ang hirap nung mga 7th, diminish and minor lines... di ko nahuhuli... or yung mga nagsisimula sa C#, hehehehe... basic ang G at C magsimula.
3.) play shred WITHOUT distortion along to a odd metered jazz back drop... now... that takes skill. di ko kaya to. without distortion, nakikita ang mga mali ng "shred" lines ko, hehehehe...